This study will examine the effects of seizures on the functional anatomy of language skills in children with both early onset and chronic epilepsy. This population provides an opportunity to gain insight into the effect of chronic neuronal dysfunction on the development of human language abilities and their brain representation. We hypothesize that seizures cause neuronal injury and force reorganization of the representation of essential cognitive skills, such as language. Patients with early epilepsy onset are expected to have greater variation in fMRI language activation patterns than those with later onset; these changes are expected to occur only after several years of epilepsy. Children will be evaluated with high resolution structural 1.5 Tesla MR.1, and functional MRI. Image data will also be transformed into a standard brain atlas to facilitate intra-subject regional comparison, as well as to account for inter-subject variability of language activation patterns. Three groups will be compared: 1) children within one year after localization related seizure onset 2) children with chronic localization related epilepsy (>3 years duration) 3) a normal control population. As a result of this study a greater understanding of the anatomic organization of language during critical periods of cognitive development and neuronal plasticity will be gained. We will determine whether seizures themselves or a common brain pathology is the driving force behind brain plasticity. Such information is important to plan intervention strategies to mitigate the sequelae of epilepsy at disease onset and in the most vulnerable children to its effects. Unlike acute and limited neuronal insults, such as head trauma and stroke, epilepsy is a chronic process with continuing but paroxysmal neuronal sequelae. Furthermore, patients may be identified and evaluated at the outset of the disease process so that the neuronal response and degree of plasticity may be assessed and monitored.